tree e73029c738cf7f2c571af30f49f7f8493afa6949
parent b7dddbc63e601298474dee68ea4c0cc25b865461
author John Wang <wangzhiqiang02@ieisystem.com> 1717505913 +0800
committer John Wang <wangzhiqiang02@ieisystem.com> 1717563027 +0800

Fix realloc() with size 0

Valgrind reported “realloc() with size 0"

'''
==508== realloc() with size 0
==508== at 0x484DB80: realloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==508== by 0x1093E3: ringbuffer_consumer_unregister (ringbuffer.c:103)
==508== by 0x10942B: ringbuffer_fini (ringbuffer.c:48)
==508== by 0x109989: test_simple_poll (test-ringbuffer-simple-poll.c:31)
==508== by 0x109A3A: main (test-ringbuffer-simple-poll.c:37)
'''

And gnu libc manual[1] said:
Portable programs should not attempt to reallocate blocks to be size
zero. On other implementations if ptr is non-null, realloc (ptr, 0)
might free the block and return a non-null pointer to a size-zero
object, or it might fail and return NULL without freeing the block.
The ISO C17 standard allows these variations.

So use free instead of realloc with size 0

[1] https://www.gnu.org/software/libc/manual/html_node/Changing-Block-Size.html
Change-Id: Ie716dd6ea84696a2091c680d71a0624423d1a185
Signed-off-by: John Wang <wangzhiqiang02@ieisystem.com>